7 November 2012. Psychotic symptoms may help identify teenagers prone to suicide, according to a study published online October 29 in Archives of General Psychiatry. Led by Mary Cannon of the Royal College of Surgeons, Dublin, Ireland, the study found that adolescents in the general population who reported psychotic symptoms were 10 times more likely to also report suicidal behaviors, including thinking, planning, or actually trying to kill themselves. Among those who thought about suicide, subjects who also had psychotic symptoms were 20 times more likely to either have planned or attempted suicide than those without these symptoms. The findings argue that psychotic symptoms should be routinely assessed in evaluations of a person’s suicide risk.

Although people with full-blown psychotic disorders like schizophrenia are much more likely to attempt suicide than the general population, the new results highlight how psychotic symptoms in the general population may also flag an increased motivation toward killing oneself, regardless of a specific diagnosis of mental illness. Epidemiology finds that psychotic symptoms, consisting of hallucinations and delusions, occur in the general population, with a higher prevalence in young people (Kelleher et al., 2012). People with these symptoms can be considered as belonging to the “extended psychosis phenotype,” in which the most severely affected have a psychotic disorder (see SRF related Webinar). These symptoms may be harbingers of future mental illness, as they are associated with increased risk for developing a psychiatric disorder, including psychotic disorders (Poulton et al., 2000). But they might be harmless symptoms, too, and researchers have seized upon the auditory hallucinations found in healthy people as a valuable inroad into the neurobiological bases of these symptoms (see SRF related Webinar).

Two groups of teens
First author Ian Kelleher and colleagues surveyed psychotic symptoms and other aspects of mental health in two separate populations of teenagers, beginning with questionnaires delivered through their schools. The first group comprised 11-13 year olds, who indicated in their answers whether they were willing to be contacted for a follow-up clinical interview. A random selection of 212 of these subjects was ultimately interviewed, during which researchers directly asked the adolescents about psychotic experiences and suicidal behaviors. The second group comprised 13-15 year olds, and after completing the questionnaires, 211 of these were interviewed. The researchers then rated the psychotic symptoms of each study participant, blind to their suicidal behaviors and diagnosis, if any.

Of those interviewed, 22 percent of the younger sample and 7 percent of the older sample reported psychotic symptoms, which consisted mainly of auditory hallucinations. These experiences significantly increased the odds of suicidal behavior (ideation, planning, or acts), giving an odds ratio of 10.23 in the younger sample and 10.50 in the older sample.

These psychotic symptoms seemed specific to suicidal behavior, rather than just indexing the early stirrings of mental illnesses, which in turn are linked to suicide. Consistent with this, when the researchers separately considered those teenagers with diagnosable psychiatric disorders, including major depressive disorder, attention-deficit/hyperactivity disorder, and anxiety disorders, they found an increased risk for suicidal behavior. Within this subset, however, the researchers also found a fivefold increase in suicidal behavior in those reporting psychotic symptoms compared to those without psychotic symptoms, suggesting a specific link between psychotic experiences and suicide.

Suicidal spectrum
The researchers also found that psychotic symptoms could help differentiate people on the more severe end of the suicidal spectrum. Among the older sample of teens who reported at least suicidal ideation, those with psychotic symptoms had a 20-fold increase in the chance of having engaged in the more severe suicidal behaviors involving plans and acts, compared to those without psychotic symptoms. The researchers also found that the majority of teens with suicidal plans or acts also reported psychotic symptoms (60 percent in the younger sample, 55 percent in the older sample).

This suggests a need to incorporate psychotic symptoms when evaluating a person for suicide risk. The researchers noted that teens rarely volunteer information about their psychotic experiences, but when asked directly, they may answer openly. Future research will have to probe the nature of the connection between psychosis and suicide. With only one person in the study reporting auditory hallucinations that commanded an act of suicide, the researchers suggest that common perturbations to brain structure and function may give rise to both psychosis and the suicidal drive.—Michele Solis.

This important study adds further weight to the utility of...
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This important study adds further weight to the utility of assessing psychotic symptoms in general population settings. It has long been routine for those who care for individuals with clinical psychotic disorders to also assess for features of depression and anxiety. In a reciprocal fashion, those involved in the care of individuals with common mental disorders such as depression and anxiety now need to routinely inquire about the presence of psychotic symptoms. While these "crossover"-type symptoms might be inconvenient for those who like to believe that psychiatric taxonomy is simple and obedient, this does not reflect the epidemiological evidence. Because psychotic experiences are associated with suicidal behavior, these items should be included in routine screening.